U.S. Pat. No. 5,120,063 which issued to Birchler et al in 1992 and U.S. Pat. No. 5,275,405 which issued to Ridge in 1994 both disclose golf practise apparatus which are designed to fit into a floor duct of a forced air heating system. Both apparatus consist of a rigid vent body adapted to fit within the floor duct and having a centrally positioned cup. The Birchler reference has air flow apertures positioned within the cup. The Ridge reference has air flow apertures positioned on either side of the cup with the air directed away from the cup so as not to influence the path of travel of the ball. The Birchler reference relies upon there being peripheral indentations in the carpet when the conventional vent is removed and the golf practise apparatus is substituted. The Ridge reference has a ramp to enable a golf ball rolling along the carpet to climb onto the golf practise apparatus.
It will be understood that while the apparatus, as described, provide a means of practising they have inherent drawbacks, which limit their ability to duplicate conditions that exist on a golf green. On a golf green, if one has the correct weight the ball will arrive at the lip of the cup and drop in. Both the references require the golf ball to leave the carpet and pass along a artificial surface to the cup. To complete a putt on the device as taught by the Ridge reference the ball must climb a ram onto a rigid metal surface. To complete a putt on the device as taught by the Birchler reference, the edge must be sunken into the carpet and the ball must pass over a textured rubber matt. A golf ball hit with what would otherwise be perfect weight can be adversely effected as it leaves the carpet surface.